Calcium and magnesium are important dietary nutrients for your overall health, but a new study looked at how these two vital minerals may impact cognitive function, too. 

The study, published in the journal Nutrients, looked at adults over 60 who were hospitalized in Poland, and compared their cognitive function to their calcium and magnesium levels. They found that the individuals who scored lower on the cognitive tests generally had lower levels of magnesium and calcium in their blood.1

Having enough calcium is key to building and maintaining strong bones. It’s also the most abundant mineral in the human body and plays a role in other vital functions, like helping with muscle and nerve health, moving blood through blood vessels, and releasing certain hormones.2

Magnesium helps regulate multiple body processes, including muscle and nerve function, blood sugar levels, and blood pressure. It is also a key nutrient for making bone and DNA.3

What the Study Found 

The researchers, based out of the Medical University of Łódź Department of Geriatrics in Poland, looked at data from 1,220 hospitalized people aged 60 and older. Unlike a previous study that measured calcium and magnesium levels through dietary intake, this new study used blood tests.4

Researchers separated participants into four groups: those with normal serum levels of magnesium and calcium, those who just had low magnesium levels, those who just had low calcium levels, and those who had low levels of both magnesium and calcium.

Participants then took two different tests to check their cognitive function. Researchers found that people with lower levels of magnesium and calcium performed worse on both cognitive tests than people with normal levels. People with normal calcium levels but low levels of magnesium also scored worse than those with normal levels of both nutrients. Those with normal magnesium levels and low calcium levels did not test as poorly.

Researchers also found that other factors, such as age, BMI, and heart failure, were linked to lower cognitive scores.

What These Study Results Actually Mean

It’s important to understand that the study shows a correlation, not causation, said Katherine Tucker, PhD, emerita professor and founder of the Center for Population Health at the Center for Digital Health at the University of Massachusetts Lowell. And, the researchers didn’t account for other factors that could have contributed to cognitive decline.

“They adjusted for heart failure, but they didn’t adjust for diabetes in terms of calcium and magnesium,” Tucker said. They also didn’t take kidney function into account, which could make magnesium and calcium levels higher or lower, Tucker said.

Hospitalized people also have higher rates of cognitive issues and may be undergoing treatment that could impact their magnesium and calcium levels, said Luke Kim, MD, a physician at the Center for Geriatric Medicine at the Cleveland Clinic. The low levels of magnesium and calcium "might be just an indicator of their illness,” he added.

Past research, including a study Tucker co-authored this year, has found similar links between magnesium levels and cognitive function, but not the same results.5

“We found that low magnesium, or high magnesium, was associated with cognitive decline, and it really is about having the balance,” Tucker said. “You want the right amount of magnesium.”

How to Get Enough Magnesium and Calcium in Your Diet 

Most adults are advised to get about 310–420 mg of magnesium and between 1,000–1,300 mg of calcium in their diet every day.32 Foods with magnesium include beans, nuts, legumes, and chia seeds. Calcium-rich foods include dairy products like milk, cheese, and yogurt, as well as dark, leafy greens like kale, broccoli, and bok choi.

If you eat a complete diet full of both calcium and magnesium, you likely don’t need additional supplements. But, almost half of Americans aren’t getting enough magnesium in the foods they eat, Tucker said.3 The reasons for this are complicated, but has to do with Americans eating more processed foods, and a decline in the mineral content of vegetables.6

If it’s difficult to get enough magnesium or calcium in your diet, you can take supplements to help you get these key nutrients. Just be sure that you’re staying within the recommended ranges.

What This Means For You

Getting enough calcium and magnesium in your diet or with supplements is important for your overall bodily functions. While a new study found that low levels of calcium and magnesium are correlated with cognitive decline, it’s not something you should be worried about in your everyday life.